Lecture 3.doc

Lecture3WaterhazardsandHumanhealthNoteAssignmentstobesubmittedtoSW223Liquid natural capitol Earth is water planetWater covers 71 of Earth surface but not all the water is available for our consumptionNot much fresh water Mostly salt water No species can do without water Sculpturing the Earths surface Water change the shape of the planet Earth ie water erosion Moderating climate Removing and diluting wastes and pollutantsPercentages on how water is used upFlushing toilets 30 Showering 35 Cleaning 5 Laundry 20 Drinking 10Canada has plenty of water available for us But some countries dont have water for basic purposesHydrological poverty One out of six people do not have regular access to clean waterPeople are walking miles to get some clean water Diarrheal deaths kill over 2 million children annuallyWater and Your Health Drinking water NEED CLEAN WATER Swimming waterDRINKING WATER Annual reports on local drinking water qualityOur right to know what we are drinking what are we consuming Naturally pure waterdistillate water Never purely 100we need some minerals in water Distilled water is free of salts Water we drink is coming from the Lake Ontario from deep inside reservoirNatural content of minerals in water Surface waterIn urban areas mostly from rivers lakes and reservoirs Ground water In rural areas wells Its underground How is drinking water treated Water from rivers lakes and reservoirsSettling tanksAddition of coagulants dirt and contaminants form clumps that settle to the bottom of the tankFilteringChemical treatment disinfection granulated activated charcoal very good for organic contaminants ion exchange resins reverse osmosis GroundwaterNaturally filtered Soil has different chemicals which purifies water Less organic matter